docs: def update_plot(self, indep_var, dep_var):
          """
          Updates the plot of the proposed model.
          """
          evaluated_model = self.ig._eval_model()
          plot = self.ig._plots[(indep_var, dep_var)]
          y_vals = getattr(evaluated_model, dep_var.name)
          x_vals = self.ig._x_points[indep_var]
          plot.set_data(x_vals, y_vals)